Wear warning device for rotating apparatus provided with an axial thrust bearing

ABSTRACT

A wear warning device for rotating apparatus provided with an axial thrust bearing, more particularly for drilling turbines, comprises a valve provided in the fluid circulation passages of the turbine, said valve being movable between an open position and a throttling position. A holding member is provided for normally retaining said valve in its open position. A helical spring is provided between said valve and a stationary member for urging said valve towards its throttling position. The holding member is rigid with the stator or rotor part of the turbine, while another member having an abrasive surface is connected to said rotor or stator part, respectively. The original distance between said abrasive surface and said holding member is substantially equal to the admissible wear clearance of the axial thrust bearing. When the wear limit is substantially reached, said abrasive surface cuts through said holding member in order to release said valve. Therefore, the valve is moved to its throttling position under the action of said spring and a pressure surge is transmitted to the surface as a warning signal.

[22] Filed:

United States Patent 1191 Tiraspolsky et al.

[ WEAR WARNING DEVICE FOR ROTATING APPARATUS PROVIDED WITH AN AXIALTIIRUST BEARING [75] Inventors: Wladimir Tiraspolsky,

, 1 lssy-les-Moulineaux; Roger Francois Rouvire, Venelles, both ofFrance [73] Assignee: Turboservice S.A.,

lssy-les-Moulineaux, France 21 Appl. No.: 297,641

[30] Foreign Application Priority Data Oct. 25, 1971 France 71.38174[52] US. Cl 116/114 Q, 188/1 A, 308/1 A, 415/118 [51] Int. Cl. GOld21/00 [58] Field of Search 116/114, 114 Q; 308/1 A,

1111 3,797,451 1451 Mar. 19, 1974 Primary Examiner-Louis J. CapOZiAttorney, Agent, or Firm-Young and Thompson [57] ABSTRACT A wear warningdevice for rotating apparatus provided with an axial thrust bearing,more particularly for drilling turbines, comprises a valve provided inthe fluid circulation passages of the.turbine, said valve being movablebetween an open position and a, throttling position. A holding member isprovided for normally retaining said valve in its open position. Ahelical spring is provided between said valve and a stationary memberfor urging said valve towards its throttling position. The holdingmember is rigid with the stator or rotor part of the turbine, whileanother member having an abrasive surface is connected to l said rotoror stator part, respectively. The original distance between saidabrasive surface and said holding member is substantially equal to theadmissible wear clearance of the axial thrust bearing. When the wearlimit is substantially reached, said abrasive surface cuts through saidholding member in order to release said valve. Therefore, the valve ismoved to its throttling position under the action of said spring and apressure surge is transmitted to the surface as a warning signal.

9 Claims, 3 Drawing Figures PATENTEU HAR I 9 1974 WEAR WARNING DEVICEFOR ROTATING APPARATUS PROVIDED WITH AN AXIAL THRUST BEARING Thepresentinvention relates generally to rotating apparatus through which flows ahydraulic current and which comprise one or more axial thrust bearings.

ln apparatus of this type, excessive wear of the axial thrust hearingmay produce serious deterioration in the mechanical part when the axialmovement resulting from the wear of the thrust bearing exceeds the magnitude of the clearance normally existing between the elements of therotor part and the stator part of the apparatus. These elements may thencome into contact, obviously producing considerable damage.

This is the case in particular in ground-drilling turbines where thethrust bearings, whether they are sliding bearings or roller bearings,may be subject to considerable axial wear, rendering doubtful theoperational reliability of such apparatus at the bottom of a well. i 1

Many solutions have already been proposed for remedying thisinconvenience.

In most of these solutions, attempts have been made to brake or stop theturbine at the moment the wear exceeds the alarm level. Such deviceshave been described, for example, in French Pat. specifications Nos.1,157.218and1.174.220.. 1

According to another proposed solution mechanical braking is replaced byby-passing of the driving fluid on the occurrence of excessive wear ofthe thrust bearing. The result is a reduction in speed of the turbinethrough lackof power. An arrangementof this type is described in FrenchPat. specification No. 1.222.715.

Despite the advantages which they provided, thes devices have not led toindustrial applications, either owing to the complexity of the cost oftheir construction, or because of the technical difficulties to whichtheir operation gives rise. s i

Attempts have also been made to remedy the aforesaid seriousdisadvantage by informing the operator at the surface, by means'of anappropriate signal, that the wear alarm level has been reached.According to one proposed method, constriction of the driving fluidducts was produced, thereby providing on the surface a significantincrease in the delivery pressure. An arrangement of this kind isdescribed in French Pat. specification No. 1.157.458. In this case, theconstriction was produced by shearing one or more pins under the effectof the rotation of a disc consequent on the braking produced by thecontact of two surfaces resulting from the axial displacement, due tothe wear of the thrust bearing. However, in view of the fact that thiswear is very gradual, there resulted a likewise gradual wear of thebraking surfaces themselves, and the desired result was not obtained.Furthermore, the con.- strictionwas produced by the relative rotation ofsuper imposed discs, which did not provide total operationalreliability. 3 a

The invention relates to devices of the said latter type, ensuringconstriction of drivingfluid ducts for producing a signal transmitted tothe surface in the form of a pressure increase, so that the operator isinformed of the fact that the wear alarm level of the thrust bearing hasbeen reached.

One object of the invention is to provide a novel device for eliminatingthe aforesaid inconveniences.

Another object of the invention is to provide a wear warning deviceadapted to be used in rotating apparatus through which passes ahydraulic current and which is provided with an axial thrust bearing, inparticular in ground-drilling turbines, of the type comprising membersensuring the constriction of the fluid ducts when the wear alarm levelof the axial thrust bearing is reached, wherein a valve movable axiallybetween an open position and a closed or throttling position is arrangedin the fluid ducts, means being provided for urging the said valvetowards its throttling position, other means normally holding the saidvalve in its open position, these latter means being connected to thesta tor part or rotor part of the apparatus, release members connectedto the rotor part or stator part of the said apparatus being arranged atan axial distance from the holding means at the most equal to theadmissible wear travel of the thrust bearing, for releasing the valve byacting on the holding means at the latest when the axial thrust bearinghas reached its admissible wear limit, the said valve then moving in theaxial direction by the action of urging means for taking its throttlingposition.

The said valve may have a number of different forms, and it may consist,for example, of a disc, piston,,flap or equivalent device, associatedwith an appropriate seat. Mounting of such a valve in the fluid ductsmay also be carried out in numerous ways, which will be readily apparentto persons versed in the art, and it will be understood that theinvention is by no means limited to a particular type of valve ormounting.

Urg ing of this valve towards its closure or throttling position mayalso be ensured in various ways, but a constructionally simple method isto provide at least one resilient member, for example a helical spring,

. urging the valve onto its seat.

The means for holding the valve in its open position advantageouslycomprise a supporting element resting on a stationary part and connectedto the movable part of the valve, the said element being severed by therelease members when the wear limit selected for the axial thrusthearing has been reached.

For releasing the valve, there is advantageously provided an abrasivesurface acting on the aforesaid means when the admissible wear limit ofthe axial thrustbearing is approached, for severing the saidholding'means by abrasion and thus releasing the valve.

When the valve is released, it is displaced abruptly by an axialmovement towards its closure or throttling position, constricting thecross-section of the fluid ducts, such that a significant pressure rise,of 20 to 30 bars for example, is produced at the surface. It will beunderstood that this signal supplied at the surface is produced as soonas the thrust bearings have reached a wear limit predetermined by thedimensioning of the axial play, in the device, between the holding meansand the release members, such that the desired result is obtained. Thethrottling produced is thus advantageously selected so that there isstill obtained a suffrcient circulation of flushing fluid for the safetyof the raising operation and even for terminating any importantoperation, it being possible to estimate the calculated risk.

The wear warning thus obtained eliminates the nonnegligible risk ofdamaging the blades by contact in addition enables the apparatus, moreparticularly the drilling turbine, to be used to the limit of its wear,resulting in a considerable increase in the service lifetime of such aturbine.

The following description made with reference to the accompanyingdrawings, given solely by way of example, will enable the invention tobe better understood. ln these drawings:

FIG. 1 shows a view in axial section of a wear warning device accordingto one possible embodiment of the invention applied to a drillingturbine.

FIG. 2 shows a view in cross-section on the line ll-ll of FIG. 1 at thelevel of the seat of the valve.

FlG. 3 shows a view in cross-section on the line lll- -lll of FIG. 1, atthe level of the apex of the suspension shoulder of the valve.

The drawings show a device acting in the direction of suspended shaftwear, that is to say in the case where the axial thrust of the turbinerotor is greater than the reaction of the hole bottom on the drillingtool.

The turbine shown in the drawings comprises a body 1, a shaft 2 havingspline flats 3, a bearing 4, 5 and sets of blades such as 6, 7 and 8 theaxial thrust bearing, known per se, is not shown here.

The warning device according to the invention is formed of aunitinserted in the rotor and stator blade sets and occupying for examplethe place of two thrust bearing stages.

According to the embodiment considered here, this device comprises astator body formed of two halfsleeves 9, 10. The half-sleeve 9 carrieson its lower part a valve seat 11. The half-sleeve 10 carries on itsupper part a supporting crown 12 in which are provided circulation ports13 for the driving fluid.

The supporting crown 12 supports a sleeve 14 by means of a rupture ring15 pinned to the crown 12 by a pin 16 connected to the seat 11 by atoroidally rounded portion 17, segmented by irrigating channels.

ln the rotor assembly of the turbine stages, there are introduced asocket 18 and a grinding disc 19 provided with a circular abrasive area20, for example provided with diamonds, and keyed at 21 to the shaft 2.

The sleeve 14 is surrounded by a helical spring 22 supported at one endon the crown 12 .and at its other end on a valve- 23 carrying on itsperiphery centring lugs 24 and supported axially by a stop ring 25.

The device just described operates as follows: When the thrust bearing(not shown) of the turbine wears, the shaft being suspended in theposition shown, the abrasive area gradually approaches the toroidalrounding 17 and grinds the latter. The calculation is such that when theadmissible wear course of the axial thrust bearing has beensubstantially completed, the said toroidal rounding is completely cutthrough, thereby eliminating the connection between the sleeve 14 andthe crown 12. Owing to the thrust of the spring 22, the said sleeve isthen forced downward with the valve 23, the lugs of which come to reston the seat 11. This throttles the passage of the driving fluid to apredetermined value, such that the corresponding rise in pressure of thecirculation current attains a significant value and a signal is thussupplied to the operator.

it will be appreciated that modifications may be made in the embodimentdescribed, in the scope of technical equivalents, without departing fromthe invention. Thus, by turning the device upside down and providing itwith a spring calibrated for compensating, once opened, the signallingback-pressure, a seated shaft warning device is obtained. By associatingor combining both devices, complete double-direction protection isobtained.

It will finally be noted that the form of signalling according to theinvention is specific andmay be distinguished from any other fortuitousrise in pressure, due for example to occlusion of the circuit. Thus, ifthe valve is closed under suspended shaft conditions, it is merelynecessary to take up the clearance due to wear by increasing the weighton the tool for lifting the valve 23 by means of the socket 18 which, bymeans of its shoulder, moves the sleeve 14, this being disclosed in arepetitive manner by a reduction in pressure. The condition is reversedin the case of a seated shaft.

What is claimed is:

1. Wear warning device for rotating apparatus through which flows ahydraulic current and'provided with an axial thrust bearing, moreparticularly for drilling turbines having a stator part and a rotorpartand fluid circulation ducts, comprising axially movable valve means.provided in said circulation ducts and movable between an open positionand a throttling position, means for urging said valve means towardssaid throttling position, holding means for normally holding said valvemeans in said open position, releasing means arranged at an axialdistance from said holding means at the most equal to the admissiblewear clearance of said axial thrust bearing, said holding means andreleasing means being connected to said rotor and stator partsrespectively, such that said releasing means re leases said valve meansby acting on said holding means at the latest when said axial thrustbearing has reached its admissible wear limit, whereby said valve urgingmeans moves said valve means to said throttling position. I

2. Wear warning device according to claim 1, wherein said valve meanscomprises a duct throttling member and a seat, said throttling memberbeing urged towards said seat by said valve urging means.

3. Wear warning device according to claim 1, wherein said means forurging said valve means towards said throttling position comprises atleast one spring member. a

4. Wear warning device according to claim 1, wherein said means forurging said valve means towards said throttling position comprises atleast one spring member the force of which is adapted to the axialdirection of movement of said valve means.

5. Wear warning device according to claim 1, wherein said means forurging said valve means towards said throttling position comprises ahelical spring.

6. Wear warning device according to claim 1, wherein said valve holdingmeans comprises a supporting member, an axially stationary element, saidsupporting member resting on said stationary element and being connectedto said movable means, and an abrasive surface provided on saidreleasing means, whereby said abrasive surface cuts said supportingmember when the wear limit of said axial thrust bearing has been reachedin order to release said supporting memher and said valve means.

7. Wear warning device for rotating apparatus through which flows ahydraulic current and provided with an axial thrust hearing, moreparticularly for drilling turbines having a stator part and a rotor partand fluid circulation ducts, comprising a stator member arranged in saidstator part, said stator member having a seat member and a stationarysupporting crown, valve -means movable between an open position and athrottling position, a movable supporting member connected to said valvemeans and resting on said stationary supporting crown, spring meanslocated between said valve means and stationary supporting crown andurging said valve means towards its throttling position, a rotor memberarranged in said rotor part, an abrasive surface provided on said rotormember, the original distance between said abrasive surface and said supporting member being at the most equal to the admissible wear clearanceof said axial thrust bearing, whereby when said axial thrust bearingwears, said abrasive sur

1. Wear warning device for rotating apparatus through which flows ahydraulic current and provided with an axial thrust bearing, moreparticularly for drilling turbines having a stator part and a rotor partand fluid circulation ducts, comprising axially movable valve meansprovided in said circulation ducts and movable between an open positionand a throttling position, means for urging said valve means towardssaid throttling position, holding means for normally holding said valvemeans in said open position, releasing means arranged at an axialdistance from said holding means at the most equal to the admissiblewear clearance of said axial thrust bearing, said holding means andreleasing means being connected to said rotor and stator partsrespectively, such that said releasing means releases said valve meansby acting on said holding means at the latest when said axial thrustbearing has reached its admissible wear limit, whereby said valve urgingmeans moves said valve means to said throttling position.
 2. Wearwarning device according to claim 1, wherein said valve means comprisesa duct throttling member and a seat, said throttling member being urgedtowards said seat by said valve urging means.
 3. Wear warning deviceaccording to claim 1, wherein said means for urging said valve meanstowards said throttling position comprises at least one spring member.4. Wear warning device according to claim 1, wherein said means forurging said valve means towards said throttling position comprises atleast one spring member the force of which is adapted to the axialdirection of movement of said valve means.
 5. Wear warning deviceaccording to claim 1, wherein said means for urging said valve meanstowards said throttling position comprises a helical spring.
 6. Wearwarning device according to claim 1, wherein said valve holding meanscomprises a supporting member, an axially stationary element, saidsupporting member resting on said stationary element and being connectedto said movable means, and an abrasive surface provided on saidreleasing means, whereby said abrasive surface cuts said supportingmember when the wear limit of said axial thrust bearing has been reachedin order to release said supporting member and said valve means.
 7. Wearwarning device for rotating apparatus through which flows a hydrauliccurrent and provided with an axial thrust bearing, more particularly fordrilling turbines having a stator part and a rotor part and fluidcirculation ducts, comprising a stator member arranged in said statorpart, said stator member having a seat member and a stationarysupporting crown, valve means movable between an open position and athrottling position, a movable supporting member connected to said valvemeans and resting on said stationary supporting crown, spring meanslocated between said valve means and stationary supporting crown andurging said valve means towards its throttling position, a rotor memberarranged in said rotor part, an abrasive surface provided on said rotormember, the original distance between said abrasive surface and saidsupporting Member being at the most equal to the admissible wearclearance of said axial thrust bearing, whereby when said axial thrustbearing wears, said abrasive surface is moved towards said supportingmember and cuts said member in order to release said valve means to bemoved towards its throttling position under the action of said springmeans.
 8. Wear warning device according to claim 7, wherein in saidthrottling position said valve means partially closes said seat member,whereby a pressure surge is transmitted to the surface to provide awarning signal.
 9. Wear warning device according to claim 7, whereinsaid abrasive surface is provided with diamonds.